RE: So it's the bits? (Was: filmscanners: Sprintscan 120 now

[Tony Sleep]

On 10 Jan 2001 09:04:51 -0800  Frank Paris ([EMAIL PROTECTED]) wrote:

>  I'm still not convinced that there's a
> necessary mapping between actual density and ADC resolution.

It's not 'necessary' inasmuch as it /could/ be done differently, but AFAIK the 
only CCD prosumer unit to do non-linear mapping was the Olympus ES10. It usually 
isn't because of cost, complexity, and the extra noise imposed by analogue 
processing - though the technique is common in PMT scanners. However it is the 
only way to escape the hard limit of DMax (=noise voltage):DMin (max volts), a 
voltage ratio which must be mapped to available bits. 

Regards 

Tony Sleep
http://www.halftone.co.uk - Online portfolio & exhibit; + film scanner info & 
comparisons